Sir Frank Williams purses his lips and rocks backwards and forwards in his
wheelchair. “I remember it all very clearly,” he says, adopting the now
familiar, rapid-fire whisper of his later years

“I was enjoying the post-race glow. I was in the garage and stopped to talk to someone and there was a sharp crack to my right. Immediately clouds of black smoke began billowing. Quick as a flash I was wheeled out of there.

"I was shouting, ‘Michael [his carer that weekend], you’ve got to f------ stop. I’m supposed to be the leader here. I can’t be running away.’ So Michael stopped and wheeled me back. But there was nothing much I could do.”

We are sitting in a downstairs meeting room at the team’s headquarters in Grove, Oxfordshire, reliving what ought to have been the unadulterated good news story of Pastor Maldonado’s historic victory, Venezuela’s first ever and Williams’ first in nearly eight years, at the Spanish Grand Prix two weekends ago.

It was what happened afterwards, however, that ended up grabbing the headlines. A raging inferno in the winners’ garage, the cause of which is still unknown, meant the celebrations came to an abrupt halt as mechanics from up and down the pit-lane battled to bring the blaze under control.

That they succeeded, with just one Williams team member still in hospital with burns to his legs (“He’s a strong character,” says Williams. “Built like the proverbial... he’ll come back when it suits him. In a month or two”), has lent the story a different hue, though it is no less inspiring. In fact, one could argue it made the occasion all the more moving.

“I was gratified to learn afterwards that every fire extinguisher in the paddock was used by pretty much every team up and down the pit-lane,” Williams says, shaking his head.

“The reaction was extraordinary. Overwhelming. All the teams have been on saying, ‘Whatever you need, we’ll help you out’. Fantastic. I don’t know exactly what we have accepted but I have asked for a list to be created.

“My main job when I get to Monaco is to go around all the team principals and thank them, and try to pay them back for whatever they gave us.”

No doubt the same support would have been offered to any team in similar straits, but it is tempting to suggest the response in this instance was particularly urgent because of the affection in which Williams, and in particular their founder, is held by the sport at large.

The evening before the Barcelona race, Williams was thrown a surprise 70th birthday party in the paddock at which the great and the good came to pay homage. From Bernie Ecclestone to former Williams drivers David Coulthard and Mark Webber, they queued up to sing the praises of “a proper racer”, whose lifelong passion for cars began in the 1950s when a friend gave him a ride in his Jaguar, who built his team from nothing and went on to claim seven drivers’ and nine constructors’ titles. They spoke of his “unquenchable spirit”, the road accident which has confined Williams to a wheelchair since 1986 having utterly failed to slow him down.

Rising costs in an era dominated by manufacturer-backed teams did, though, and the team’s decline over the last decade was painful to watch. Somehow they appear to be back from the brink.

Williams admits that the thought that he would never again see one of his cars win a grand prix had crossed his mind.

“It wasn’t so much the fear,” he says. “There was just a stronger and stronger sense of embarrassment. As the years went by and we started disappearing and it was too late to jump, you know?

“But I can’t say I spent weeks lying in bed worrying about it. Fortunately better people than myself came along and sorted it out.”

One of the people to whom he is referring is former chairman Adam Parr, who left the company in mysterious circumstances earlier this season. Williams will still not be drawn on the “private” reasons why that happened but says he would not be surprised to see him back in the sport, “possibly on the commercial side”.

“He has a brilliant mind,” he says. “I speak to him often. He is delighted for the team and should take his share of the credit. All of the top people here — well, not all of them, but quite a few — were recruited by Adam: Mike Coughlan, Jason Somerville, Ed Wood.”

That all-new technical team is just one element of the sweeping changes which have enabled Williams to make a far more encouraging start to 2012. There is also a new engine supplier in Renault, a new driver in Bruno Senna, while Williams’ co-founder, Patrick Head, quit the team over the winter. “He was a bit jealous he wasn’t part of [the win] but he was fundamental to it,” Williams says.

By luck or judgment the drastic overhaul seems to have worked.

Williams is certainly getting excited again. His eyes light up at the thought of Monaco this weekend. Does he believe his team can rise from the ashes of Barcelona to post another win?

“Yes. I do,” he says after a lengthy pause. “Barcelona was a surprise but we knew we had improved. The car is very nicely balanced. And the biggest surprise, or pleasure, is to find Maldo is very, very competitive. Totally apolitical. And brings in useful amounts of sponsorship.”

‘Useful’ is one word for a reputed £29.4 million this year alone from Venezuelan state-owned oil company PDVSA.

“Now Bruno must respond. Maldo’s win will give him a kick up the backside. Which he needs. We’ll see. Everyone is saying Maldo is magic around Monte Carlo and to some extent he is [the Venezuelan has won in every other category he has raced in at the Principality]. But it is by no means a given.

“Formula One is vicious. If you make the slightest mistake, you’re dead. So it’s best to show humility.”

As he rattles on, warming to the theme, it is impossible not to marvel at the enthusiasm which still shines through at 70.

How long can he keep it up? That is the question - and one you suspect informed the reaction in Spain. Williams referred to the “gradual but inevitable process of handing over the reins” in a pre-season statement in which he announced he was stepping down from the board of directors.

“It doesn’t really change anything,” he smiles now of that decision.

“Whether I go to the board meetings or not doesn’t change anything.

“All the individuals with their divisional responsibilities do a super job. I’m still the controlling shareholder and team principal.”

So what would it take to slow him down? “Someone has got to say to me,